Some stereo microscope with special accessories can be used for professional jewelers and gemologists, as stereo microscope can supply a wide field of view. The dual halogen illuminator can provide a switchable brightfield and darkfield with an iris aperture for transmitted lighting. A front incandescent lamp can provide a reflected illumination for surface inspection. The gem-tweezer can be swiveled and twisted for precise positioning. If you need mount a camera, trinocular head microscope is a good choice.
Check more details about Qualitek microscope which can be used in this field.